Embodiments disclosed herein relate to methods for enhancing purification of proteins, including antibodies. In particular, embodiments relate to methods for reducing the level of aggregates. Such methods may be performed in conjunction (sequentially or simultaneously) with clarification of cell culture harvest. Embodiments disclosed herein further relate to integration of these capabilities with other purification methods to achieve the desired level of final protein purity.
Aggregate removal has recognized value in protein purification. It has been shown that low concentrations of the yellow fluorescent heterocyclic dye ethacridine reduced aggregate content of antibody preparations (Gan et al J. Chromatography A 1291 (2013) 33-40). Ethacridine is used as a precipitating agent in the field of protein purification.
The thio-heterocyclic cation methylene blue is used to inactivate virus of therapeutic protein preparations produced by fractionation of blood plasma. It is also used as an anti-malarial drug and for treatment of methemoglobinemia and certain cancers.